In this letter we model the deviation of the nominal exchange rate from the long run equilibrium level predicted by monetary fundamentals in a nonlinear framework consistent with the presence of transaction costs. We consider a novel approach that allows for the joint testing of nonlinearity and...

We consider a new method to estimate causal effects when a treated unit suffers a shock or an intervention, such as a policy change, but there is not a readily available control group or counterfactual. We propose a two-step approach where in the first stage an artificial counterfactual is...

This paper investigates the regional differences in the spread of COVID-19 infections in Germany. A machine learning selection procedure is used to reduce variables from a pool of potential influencing variables. The empirical analysis shows that both regional structural variables and regionally...